US 3752201 A
A simple linkage is provided for transferring cylindrical blocks of wood in horizontal movement from the yokes of a pre-centering cradle to the chucks of a veneer lathe. The block is transferred by a pair of chucking arms which grip the ends of the block at points off center from the lathe chucking centers. The blocks are carried by the lower ends of the chucking arms which swing in a complex movement from overhead supporting mechanism. The movements of the chucking arms are controlled by wheels rolling on a pair of cam plates and a pair of link arms which together impart approximately straight line horizontal movement to the blocks instead of an undesirable arcuate path of movement.
Description (OCR text may contain errors)
Unite States Patent [191 [451 Aug. 14, 1973 Kieth VENEER LATHE CHARGER  Inventor: Edwin M. Heth, 4310 S.E. 35th Pl., Portland, Oreg. 97202; John W. Tidland, 213 N. W. 94th St., Vancouver, Wash.
 Filed. May 2 5 :1972 mm 7' Q  Appl. No.: 256,894
 US. Cl 144/209 A  Int. Cl B271 5/04  Field of Search... 144/209 A, 209 R, 144/208 R; 82/45  References Cited UNITED STATES PATENTS 3,037,538 6/1962 Graham 144/209 A 3,088,505 5/1963 Pearson 144/209 R 3,664,395 5/1972 Reed l44/209A Primary Examiner-Donald R. Schran Attorney-Lee R. Schermerhorn [5 7] ABSTRACT swing in a complex movement from overhead supporting mechanism. The movements of the chucking arms are controlled by wheels rolling on a pair of cam plates and a pair of link arms which together impart approximately straight line horizontal movement to the blocks instead of an undesirable arcuate path of movement.
11 Claims, 4 Drawing Figures Patented Aug. 14, 1973 3,752,201
3 Sheets-Sheet 1 Patented Aug. 14, 1973 3,752,201
3 Sheets-Sheet 2 Patented Aug. 14, 1973 3 Sheets-Sheet 5 BACKGROUND OF THE INVENTION This invention relates to a veneer lathe charger.
As the available supply of large peeler logs becomes exhausted, smaller logs must be used, increasing the number of chucking operations which must be performed to produce a given quantity of veneer. This has resulted in the development of various types of lathe loaders or chargers aimed at reducing the time required to get a new log or block into the lathe so that there will not be long interruptions in the production of veneer.
Devices heretofore proposed for this purpose have been quite complicated and expensive. Also, they have been cumbersome in their space requirements, interfering with auxiliary equipment adjacent or on the lathe and in some cases requiring excessive overhead clearance.
Objects of the invention are, therefore, to provide an improved veneer lathe charger, to provide a charger of relatively simple and inexpensive construction, to provide a compact mechanism for the purpose described which moves cylindrical blocks in a horizontal path into lathe chucks, and to provide a mechanism having swinging chucking arms which move in an approximately straight line path rather than a circular arc.
SUMMARY OF THE INVENTION In the present construction, cylindrical blocks of wood are transferred by a pair of chucking plateswhich grip the ends of the blocks in off center position so as to leave the centers accessible to the lathe chucks. These chucking plates are mounted on the lower ends of a pair of depending chucking arms which swing from an overhead supporting mechanism. The path of movement of the arms is determined by wheels riding on cam plates and link arms connected with the upper ends of the chucking arms. This mechanism is very compact having minimum clearance requirements in the space adjacent the lathe and not requiring a high overhead clearance.
The invention will be better understood and additional objects and advantages will become apparent from the following description of the preferred embodiment illustrated in the accompanying drawings. Various changes may be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the inventron.
BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 the lathe has a pair of chucks 11 which are movable axially to receive and grip the centers of the cylindrical block of wood B and rotate the block against the veneer peeler knife assembly 12. The sheet of veneer thus produced is discharged from the right side of the machine on a suitable conveyor, not shown. The blocks approach on an infeed conveyor 15 on the left side. Conveyor 15 is arranged to deposit a block on a cradle comprising a pair of lower yokes when these'yokes are retracted to the lower position at 20a.
Each lower yoke 20 is mounted on a slide 21 which may be raised and lowered in a vertical guide 22 by a cylindrical 23 and piston rod 24. The yoke is laterally adjustable by a cylinder and piston unit 25. For this purpose the guide 22 is pivotally supported at 26.
In the operation of pre-centering the ends of the block, the upper side of the block is engaged by a pair of upper yokes 30. Each upper yoke is mounted on a slide 31 in a vertical guide 32, the yoke being raised and lowered by a cylinder 33 and piston rod 34.
Extending between the yokes 20 and lathe 10 is a trough 35 having a core conveyor 36 to remove the core blocks remaining when the block B has been reduced to such size that no more veneer can be removed therefrom.
The lower and upper yokes 20 and 30 at opposite ends of the block are adjusted by automatic mechanism to automatically pre-center the ends of the block on the level of lathe chucks l1 and at a predetermined horizontal distance from the axis of the lathe chucks. This mechanism is well understood by persons skilled in the art and forms no part of the present invention.
The parts thus far described are conventional and will not be elaborated in further detail. The present invention involves the charger which transfers the block B from its pre-centered position on the lower yokes 20 to the lathe chucks 11 after the upper yokes 30 have been retracted to their raised positions at 30a.
The charger is mounted on a horizontal main frame 40 having a bracket 41 at each end with a pin 42 providing pivotal connection with one end of a link arm 43. The opposite ends of link arms 43 are connected to a shaft 44 in the upper portion of a charger pivot frame 45. The lower portion of charger pivot frame 45 carries a shaft 46 with a wheel 47 at each end.
Each wheel 47 rides on a cam plate 50 having a slightly upwardly inclined track surface 51 on its left end in FIG. 1 and a more steeply downwardly inclined track surface 52 on its right end. This cam plate is mounted on the main frame 40 with its highest point approximately directly under shaft 44. Above the cam plate is a similarly shaped wheel retainer plate 53. The lower portion of pivot frame 45 at each end thereof is pivotally connected at 55 with a piston rod 56 in a transfer cylinder 57. At the lower end of inclined surface 52 on the cam plate 50 at each end of the pivot frame is a shock absorber 58 on a mounting bracket 59.
Mounted oneach end of pivot frame 45 is a chucking.
arm 60. The lower end of each chucking arm 60 carries a chucking plate 61. As shown in FIG. 4, the lower end of the chucking plate is cut back in a V-shape as indicated at 62 in order to approach as closely as possible to the lathe chuck 11. An arcuate arrangement of pointed pins 63 is arranged to support small blocks B for transfer to the lathe and a plurality of semi-circular spikes 64 is disposed on a larger arc to engage larger blocks B in addition to the support provided by pins 63.
As shown in FIG. 3, the chucking arms 60 include plates having bearings 71 and 72 to slide on the shafts 44 and 46. A bracket 73 on each plate 70 ispivotally connected at 74 with a piston rod 75 in a cylinder 76. Each cylinder 76 is pivotally connected at 77 with a bracket 78 on a plate 80 which is a part of the pivot frame 45. Thus, the chucking plates 60 may be pulled toward each other to grip and transfer a block to the lathe chucks 11 and then moved away from each other to release the block. IN FIG. 3 the chucking arms are in the intermediate position indicated at 60a in FIG. 1.
When a block B has been pre-centered as above described on the two lower yokes 20, the retraction of piston rod 56 will swing the chucking arms 60 to the position shown in solid lines in FIG. 1 with piston rods 75 extended. Retracting the piston rods 75 causes the chucking plates 61 to grip the ends of the block and extension of piston rod 56 rolls the wheels 47 on cam plates 50, first up the slight incline of track surface 51 and then down the steeper incline of track surface 52 to the broken line position of the chucking arms at 60b in FIG. 1. At this point the movement of pivot frame 45 is arrested by shock absorbers 58 bringing the block B to rest with its center line on the center line of lathe chucks 11 for transfer of the block from chucking plates 61 to the lathe chucks.
During this transfer movement, the center line of the block B follows on the path line 90 which departs only slightly from a straight horizontal line. Even a large block as indicated at B safely clears the core conveyor 36. The charger does not require modification of any of the conventional equipment and does not require extra overhead clearance as is necessary with long, pendulous chucking arms which swing the block in a circular arc. No part of the charger projects above the conventional upper yoke assemblies 31, 32. Further, the present charger does not interfere with core conveyor 36 as do previously proposed chucking arms which are pivoted at their lower ends and swing the block in a circular are at their upper ends.
Before the described transfer movement is initiated, both lower and upper yokes and are retracted to positions 20a and 30a.
It is desired to provide for field adjustment of each cam plate 50 at the time of installation.- Adjusting screws 91 shift cam plate 50 right or left in FIG. 1 as may be necessary to produce the desired path of travel 90 under variable conditions encountered in the field. This adjustment is made before retainer plate 53 is installed.
Having now described our invention and in what manner the same may be used, what we claim as new and desire to protect by Letters Patent is:
I. A veneer lathe charger for transferring cylindrical blocks in approximately straight line horizontal movement to the lathe chucks from a pre-centered position in a location at one side of the lathe, comprising a charger pivot frame having a pair of depending chucking arms at opposite ends of said frame with chucking plates arranged to clamp the opposite ends of the block in off center positions at said location, a pair of wheels on a lower portion of said pivot frame at said opposite ends thereof, a pair of cam plates supporting said wheels for travel thereon, a pair of transversely extending link arms pivotally connected at one end to an upper portion of said pivot frame at opposite ends thereof, the opposite ends of said link arms being connected to stationary pivot means, and means for moving said lower portion of said pivot frame on saidcam plates, said cam plates having inclined tracks for said wheels which move said chucking plates in approximately straight horizontal paths of travel from said location to said lathe chucks.
2. A charger as defined in claim 1, said moving means comprising cylinder and piston units connected to said lower portion of said pivot frame.
3. A charger as defined in claim 1, said cam plate tracks having an upward inclination to guide the first part of said movement and a downward inclination to guide the latter part of said movement.
4. A charger as defined in claim 3, the highest point of said cam tracks being approximately directly under the axis of the pivotal connections between said link arms and said pivot frame.
5. A charger as defined in claim 3 including shock absorbers arranged to arrest the movement of said pivot frame at the lower end of said downward inclination.
6. A charger as defined in claim 1, said pivot frame having an upper longitudinal shaft connected to said link arms and a lower longitudinal shaft carrying said wheels.
7. A charger as defined in claim 6, said chucking arms being mounted for sliding movement on said upper and lower shafts.
8. A charger as defined in claim 7 including cylinder and piston means for moving said chucking arms on said upper and lower shafts.
9. A charger as defined in claim 8, said cylinder and piston means comprising a first cylinder and piston unit connected between the center of said pivot frame and one of said chucking arms and a second cylinder and piston unit connected between the center of said pivot frame and the other chucking arm.
10. A charger as defined in claim 1, each of said chucking plates having an inner arc of pointed cylindrical pins and an outer arc of sharpened semi-circular spikes to engage said block.
11. A charger as defined in claim 1 including means to adjust said cam plates longitudinally.